package daemon import ( "fmt" "net/http" "time" "github.com/Sirupsen/logrus" "github.com/docker/docker/api/errors" "github.com/docker/docker/container" ) // ContainerStop looks for the given container and terminates it, // waiting the given number of seconds before forcefully killing the // container. If a negative number of seconds is given, ContainerStop // will wait for a graceful termination. An error is returned if the // container is not found, is already stopped, or if there is a // problem stopping the container. func (daemon *Daemon) ContainerStop(name string, seconds *int) error { container, err := daemon.GetContainer(name) if err != nil { return err } if !container.IsRunning() { err := fmt.Errorf("Container %s is already stopped", name) return errors.NewErrorWithStatusCode(err, http.StatusNotModified) } if seconds == nil { stopTimeout := container.StopTimeout() seconds = &stopTimeout } if err := daemon.containerStop(container, *seconds); err != nil { return fmt.Errorf("Cannot stop container %s: %v", name, err) } return nil } // containerStop halts a container by sending a stop signal, waiting for the given // duration in seconds, and then calling SIGKILL and waiting for the // process to exit. If a negative duration is given, Stop will wait // for the initial signal forever. If the container is not running Stop returns // immediately. func (daemon *Daemon) containerStop(container *container.Container, seconds int) error { if !container.IsRunning() { return nil } daemon.stopHealthchecks(container) stopSignal := container.StopSignal() // 1. Send a stop signal if err := daemon.killPossiblyDeadProcess(container, stopSignal); err != nil { // While normally we might "return err" here we're not going to // because if we can't stop the container by this point then // its probably because its already stopped. Meaning, between // the time of the IsRunning() call above and now it stopped. // Also, since the err return will be environment specific we can't // look for any particular (common) error that would indicate // that the process is already dead vs something else going wrong. // So, instead we'll give it up to 2 more seconds to complete and if // by that time the container is still running, then the error // we got is probably valid and so we force kill it. if _, err := container.WaitStop(2 * time.Second); err != nil { logrus.Infof("Container failed to stop after sending signal %d to the process, force killing", stopSignal) if err := daemon.killPossiblyDeadProcess(container, 9); err != nil { return err } } } // 2. Wait for the process to exit on its own if _, err := container.WaitStop(time.Duration(seconds) * time.Second); err != nil { logrus.Infof("Container %v failed to exit within %d seconds of signal %d - using the force", container.ID, seconds, stopSignal) // 3. If it doesn't, then send SIGKILL if err := daemon.Kill(container); err != nil { container.WaitStop(-1 * time.Second) logrus.Warn(err) // Don't return error because we only care that container is stopped, not what function stopped it } } daemon.LogContainerEvent(container, "stop") return nil }